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排序方式: 共有615条查询结果,搜索用时 15 毫秒
101.
Quan Xue Kam Man Shum Chi Hou Chan 《Microwave and Wireless Components Letters, IEEE》2001,11(5):202-204
A novel transistor oscillator incorporating a compact microstrip resonant cell (CMRC) as its terminating resonance is proposed. Adjusting the dimensions of the cell, it is possible that the fundamental frequency can be positively fed back and the second harmonic negatively fed back at the input port of the oscillator. The fundamental output is enhanced with the second harmonic being suppressed. The output power of the proposed CMRC oscillator is 14.7 dBm at 2.5 GHz with 27.1 dB rejection of the second harmonic, outperforming the conventional microstrip termination with a 40% size reduction 相似文献
102.
This study investigated the effect of steam cooking on distribution of paralytic shellfish poisoning toxins (PSP-toxins) in scallops Patinopecten yessoensis. Toxins analysis by high-performance liquid chromatography showed that most of the PSP-toxins (>70%) were accumulated in viscera and adductor muscle of the raw scallops. Steam cooking induced significant loss (p < 0.05) of PSP-toxins from viscera (16%), adductor muscle (24%), gill and mantle (11%) while 32% of the toxins were retained inside viscera and adductor muscle. Overall, 51% of PSP-toxins leaked out from scallop tissues during steam cooking. However, there was no significant loss (p > 0.05) of PSP-toxins from gonad. Consumption of viscera was the most significant risk factor for causing PSP, while gonad and scallop soup were the second most significant. A rapid PSP test further verified detectable levels of PSP-toxins in all samples. However, possible interfering substance(s) in adductor muscles and gonads might potentially affect the results from this test. 相似文献
103.
Rainflow counting algorithm for very long stress histories 总被引:2,自引:0,他引:2
A computer algorithm for rainflow cycle counting of very long stress histories is presented. The procedure enables the rainflow counting to be performed without prior knowledge of the whole stress history being analysed. The stress history can be read and analysed by the computer one block at a time without reading the whole history at once. This will enable small computers to analyse very long stress histories because the length of one block can be adjusted to the computer capabilities. The algorithm does not require any rearrangment of the stress history before the start of counting and the peaks and troughs can be analysed as they were recorded in service. 相似文献
104.
Jong‐Chul Yoon Hyeong Ryeol Kam Jeong‐Mo Hong Shin Jin Kang Chang‐Hun Kim 《Computer Graphics Forum》2009,28(7):1853-1859
We propose a fast and effective technique to improve sub‐grid visual details of the grid based fluid simulation. Our method procedurally synthesizes the flow fields coming from the incompressible Navier‐Stokes solver and the vorticity fields generated by vortex particle method for sub‐grid turbulence. We are able to efficiently animate smoke which is highly turbulent and swirling with small scale details. Since this technique does not solve the linear system in high‐resolution grids, it can perform fluid simulation more rapidly. We can easily estimate the influence of turbulent and swirling effect to the fluid flow. 相似文献
105.
Zhao Yan Yu Han Liying Lin Ying Xue Chao Ma Wai Kit Ng Kam Sing Wong Kei May Lau 《光:科学与应用(英文版)》2021,(11):2143-2152
The deployment of photonic integrated circuits (PICs) necessitates an integration platform that is scalable, high-throughput, cost-effective, and power-efficien... 相似文献
106.
This paper compares the effects of different forms of vulcanized natural rubbers on the physical, mechanical, thermal, and electrical performances of filled epoxy systems. In this study, natural rubber (NR), liquid natural rubber (LNR), and recycled natural rubber (rNR) were introduced into filled epoxy systems. The results show that flexural strength, modulus, and toughness properties of filled epoxy system were enhanced with NR phases, as compared to those with LNR and rNR. Scanning electron micrograph revealed that the particle sizes of NR phases dispersed within epoxy matrix were smaller and more uniform, as compared to those with LNR and rNR phases. Incorporation of NR phases has improved the thermal stability of filled system, followed by LNR and rNR. This is attributed to more heat energy needed to overcome good interfacial bonding between epoxy matrix and small NR phases. X-ray diffraction analysis result showed that filled epoxy/NR/GNP system has higher 2θ values, indicated that d-spacing in between GNP nano-fillers has the closer distance. Electrical bulk conductivity values of filled epoxy/NR/GNP system were the highest. Small NR phases acted as elastomer spacers, which provided better “GNP packing efficiency” and realigned the GNP nano-fillers to form more effective conductive pathways for electrons hopping. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47188. 相似文献
107.
A scaling analysis is performed to study transport phenomena in the supercritical fluid extraction process. Two typical systems, one solid-fluid and one liquid-fluid, are investigated. Characteristic velocities and time scales of each transport process are determined by force balances. The dominant driving force in each existing phase and the race-determining factor of the entire system are identified. Enhancements of practical applications towards more energy efficient operations are suggested. For situations with insufficient solute transport, different methods of improvement are discussed. 相似文献
108.
109.
Correlation averaging was used to enhance the three-dimensional spherical harmonic expansion of human wart virus particles from randomly-oriented negatively-stained electron microscopic images in holey grids. The reconstruction reveals the coat protein arrangement and variations in stain distribution inside the virus core. Selection rules imposed by the spherical symmetry on the harmonic expansion component are obtained indeed for angular momenta, l, lower than 11, but cannot be shown for l greater than or equal to 11, due to non-spherical distortions of about 1/11th of the radius of the virus. This prevents us from resolving fine details of packing of the protomers on the surface lattice. Distribution of stain inside the virus core, and its spherical symmetry, is reconstructed and may be related to nucleic acids and core protein structure. 相似文献
110.
Kam A.C. Kai-Yeung Siu Barry R.A. Swanson E.A. 《Lightwave Technology, Journal of》1998,16(12):2265-2280
This paper presents the design of a cell-switching wavelength division multiplexing (WDM) local area network (LAN), which constitutes a key component of a next-generation internet (NGI) consortium project recently funded by DARPA. An important goal of the NGI project is to support bandwidth-on-demand services with quality-of-service (QOS) guarantee over WDM networks. As a first step toward this goal, we have developed several fast scheduling algorithms for flexible bandwidth reservations and fair sharing of unreserved bandwidth in a WDM broadcast network with fast-tunable transceivers. Unlike circuit-based bandwidth reservation schemes that impose a fixed schedule precomputed on setup, our scheme deals with bursty traffic by allocating network resources dynamically using very efficient algorithms. Our algorithms are based on a new concept of computing maximal weighted matchings, which is a generalization of maximal matchings on unweighted graphs. We prove that our algorithms can support total reserved bandwidth of up to 50% of the network capacity, and in that case constant delay bounds are also established. Simulations show that our algorithms can in practice support much higher reserved bandwidth-up to 90% of network capacity, and with much better delay bounds, even for burst traffic. In addition to the bandwidth guarantee, the unreserved bandwidth can be shared fairly among the users using our fair access algorithms with case to 100% network utilization in simulations 相似文献